Cooler box with temperature control function and temperature control method thereof

ABSTRACT

A cooler box with a temperature control function, the cooler box comprises a box body and a cryogenic medium container installed outside the cooler box for storing liquid carbon dioxide or other liquefied gas. The box body is equipped with a controller, a monitoring device, a controllable valve, and a chamber to reduce the speed of gas released and thus prevent sudden freezing and overcooling of temperature-sensitive cargo such as fresh food. The controllable valve is connected to the cryogenic medium container through a tube. The monitoring device measures the temperature inside the cooler box, and the controller controls the valve opening state and the duration time of maintaining the open state of the controllable valve according to the temperature measured by the monitoring device and the size of the cooler box. A temperature control method for the cooler box is also provided.

FIELD

The subject matter herein generally relates to temperature control, and more particularly, to a cooler box with a temperature control function, and a temperature control method thereof.

BACKGROUND

The cold chain industry, in order to guarantee the safety of the fresh foods being delivered, must ensure that the ambient temperature of the containers for foods is maintained within the right temperature range during the entire transportation process.

The low-temperature preservation containers used for fresh food during the transportation, shipment, and storage processes is usually a refrigerated box with thermal insulation.

Passive refrigeration is to place a pre-cooled and low-temperature medium, such as ice pads or ice bricks, in the refrigerator. The advantages of passive refrigeration are low cost, environmental friendly (the ice pads can be reused), unplugged, and high mobility. The disadvantage is that the low-temperature medium must be cooled before use and such cooling time is long. Therefore, when the temperature inside the box is higher than the required storage temperature, the food can become unsafe.

Active refrigeration uses a compressor to produce cold air to maintain the required low temperature for a long time, e.g., a mobile refrigerator. The advantages of active refrigeration are that it can keep fresh food at the desired temperature for a long time and can be used at any time with-out pre-cooling. The disadvantages are high cost, power consumption and low mobility.

Achieving an economic and practical compromise between these two systems is problematic.

BRIEF DESCRIPTION OF THE DRAWINGS

Implementations of the present technology will now be described, by way of embodiment, with reference to the attached figures, wherein:

FIG. 1 is a schematic block diagram of one embodiment of a cooler box according to the present disclosure.

FIG. 2 is a schematic block diagram of another embodiment of a cooler box according to the present disclosure.

FIG. 3 is a flow chart of one embodiment of a temperature control method of the cooler box of FIG. 2 according to the present disclosure.

FIG. 4 is a schematic block diagram of another embodiment of a cooler box according to the present disclosure.

FIG. 5 is a flow chart of one embodiment of a temperature control method of the cooler box of FIG. 4 according to the present disclosure.

DETAILED DESCRIPTION

It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, methods, procedures, and components have not been described in detail so as not to obscure the related relevant feature being described. Also, the description is not to be considered as limiting the scope of the embodiments described herein. The drawings are not necessarily to scale and the proportions of certain parts may be exaggerated to better illustrate details and features of the present disclosure.

References to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean “at least one”.

In general, the word “module” as used hereinafter, refers to logic embodied in computing or firmware, or to a collection of software instructions, written in a programming language, such as, Java, C, or assembly. One or more software instructions in the modules may be embedded in firmware, such as in an erasable programmable read only memory (EPROM). The modules described herein may be implemented as either software and/or computing modules and may be stored in any type of non-transitory computer-readable medium or other storage device. Some non-limiting examples of non-transitory computer-readable media include CDs, DVDs, BLU-RAY, flash memory, and hard disk drives. The term “comprising”, when utilized, means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in a so-described combination, group, series, and the like.

FIG. 1 illustrates a cooler box 100 with a temperature control function in one embodiment. The cooler box 100 comprises a box body 110, a cryogenic medium container 120 and a controllable valve 122, wherein the cryogenic medium container 120 and the controllable valve 122 are connected through a tube. In one embodiment, the box body 110 is a sealable box comprising two shells with a void between them, the void being component installation cavity 111 for the installation of the controllable valve 122. The inner layer or skin of the two shells further comprises an air inlet 115. The box body 110 further comprises a divider plane 112, which divides the inner part of the box body 110 into a speed deceleration area 113 and a storage area 114. The divider plane 112 comprises a plurality of uniformly distributed openings. The storage area 114 is configured for a user to place food products to be transported at low temperature. The cryogenic medium container 120 comprises an air outlet, the control valve 122 comprises a valve inlet and a valve nozzle, the air outlet of cryogenic medium container 120 and the valve inlet of the controllable valve 122 are connected through a tube, and the valve nozzle of the controllable valve 122 is connected through another tube to the air inlet 115.

In one embodiment, the controllable valve 122 is a battery powered electronic device. The controllable valve 122 comprises a valve, and the controllable valve 122 controls the opening of the valve and the size when open and maintains the opened size to a preset time duration according to preset operating parameters. In one embodiment, the preset operating parameters comprise Vs and Vt, in which Vs represents the opened size and Vt represents the preset time duration. Specifically, the opened size can comprise closed, half open, and fully open, and the preset time duration is measured in minutes.

In one embodiment, the cryogenic medium container 120 contains liquid gas, and when the valve of the controllable valve 122 is opened, the liquid gas vaporizes. Since the liquid gas is stored in the cryogenic medium container 120 at high pressure, the gas allowed to enter the valve inlet of the controllable valve 122 from the air outlet of cryogenic medium container 120 will have a very high velocity and very low temperature because of the expansion from liquid to gas. If the gas is sprayed directly into the interior of the box body 110, onto the food products being transported, the products would be suddenly frozen, to a temperature which is lower than their required temperature fresh fruits and vegetables being most vulnerable to freezing. Therefore, in the embodiment, the speed deceleration area 113 is a large chamber for significantly reducing the speed, and therefore freezing effect, of the gas flow from the air inlet 115. The physical characteristics of the cooler gas/air cause it to sink down, through the uniformly distributed openings of the divider plane 112, and slowly and uniformly to enter the storage area 113, to ensure that a temperature of the storage area 113 is uniformly decreased to the required lower temperature.

In one embodiment, the controllable valve 122 can accept a plurality of sets of (Vs, Vt) operating parameters. After the controllable valve 122 starts operating, it sequentially cycles through each of the plurality of sets of operating parameters until it stops operating or a new operating configuration is set.

In one embodiment, the controllable valve 122 controls the valve according to two sets of operating parameters, which are the first set of operating parameters (Vs₀, Vt₀) and the second set of operating parameters (Vs₁, Vt₁). The first set is the operating parameters for the insulation condition and the second set is the operating parameters for the cooling condition. In one example, after the controlled valve 122 starts operating, it first executes the first set of operating parameters (Vs₀, Vt₀) for the insulation condition, then executes the second set of operating parameters (Vs₁, Vt₁) for the cooling condition, and continues to cycle through the above actions until the controllable valve 122 stops operating. Specifically, Vs₀ comprises closed and slightly open, Vs₁ comprises fully open, the time duration of Vt₀ being longer than the time duration of Vt₁. For example, after the controllable valve 122 begins operation, it first maintains the valve opening at Vs₀ (e.g., closed or slightly open) for a duration Vt₀ (e.g., 30 minutes), then adjusts the valve opening to Vs₁ (e.g., fully open) for a duration Vt₁ (e.g., 1 minute), and continues to cycle through the above actions.

Since the controllable valve 122 is connected to the cryogenic medium container 120 through a tube, when the valve of the controllable valve 120 is opened, the liquid gas inside the cryogenic medium container 120 is vaporized and enters the interior of the box body 110 through the air inlet 115 at very low temperature. By setting the above two sets of operating parameters, the temperature inside the box body 110 is easily maintained between the temperature upper limit value and the temperature lower limit value required for the preservation of the food products inside the box body 110 to ensure food safety. Specifically, the two sets of operating parameters are determined in advance based on the temperature range required for the food products inside the cooler box 100 (a temperature range comprising of the temperature upper limit value and the temperature lower limit value), the internal space of the cooler box 100, the temperature of the ambient environment and other parameters, and then sent to the controllable valve 122. The controllable valve 122 comprises a human-machine interface which allows the user to configure sets of operating parameters and to display the configured sets of operating parameters. The controllable valve 122 cycles through the opening and closing of the valve according to the configured sets of operating parameters to achieve the purpose of the cooler box 100.

In one embodiment, the cooler box 100 comprises an upper lid that fits over the box body 100, with the speed deceleration area 113 and the divider plane 112 provided in the internal heat insulation space of the upper lid.

FIG. 2 illustrates a cooler box 200 with a temperature control function in another embodiment. The cooler box 200 comprises a box body 210, a controller 212, a monitoring device 214, a cryogenic medium container 220, and a controllable valve 222, wherein the controller 212, the monitoring device 214 and the controllable valve 222 are disposed inside the box body 210. The controller 212, the monitoring device 214 and the controllable valve 222 are electrically connected to each other, and the cryogenic medium container 220 is connected to the controllable valve 222. In one embodiment, the cryogenic medium container 220 is mounted on the exterior of the box body 210 for easy replacement by the user. In other embodiments, the controller 212, the monitoring device 214 and the controllable valve 222 are connected by wireless communication. The cryogenic medium container 220 is disposed inside the box body 210.

In one embodiment, the cryogenic medium container 220 is used to store liquid gas, wherein the liquid gas comprises liquid carbon dioxide and liquid nitrogen and such. The cryogenic medium container 220 is a cylinder, the outlet of the cylinder is connected to the controllable valve 222, the controllable valve 222 comprises a valve inlet and a valve nozzle, wherein the valve inlet is connected to the outlet of the cryogenic medium container 220. An air inlet is provided in the interior wall of the box body 210, and the valve nozzle is connected to the air inlet through a tube. The monitoring device 214 comprises a temperature sensor for sensing the internal temperature of the box body 210 and reporting it periodically to the controller 212, which receives monitoring data form the monitoring device 214 and controls the opening size and opening time duration of the controllable valve 222 to control the amount of liquid gas released based on the received monitoring data. The monitoring data comprises temperature values. Specifically, the controllable valve 222 can be an electronic device powered by a battery and can receive instructions form the controller 212 to control the opening and closing of its valve, the time duration of opening, the size of the opening and the multi-stage opening setting. This embodiment uses the principle of liquid expanding and cooling into gas, to achieve the cooler box 200 being maintained within a proper temperature range for fresh food preservation.

In one embodiment, the box body 210 further comprises two shells with a component installation cavity to avoid contamination of the hardware components. In the embodiment, the monitoring device 214 further comprises a temperature probe, wherein the temperature probe of the monitoring device 214 passes through the inner shell of the two-layer shell such that the temperature probe is placed inside the box body 210 for sensing the internal temperature of the box body 210. In other embodiments, the controller 2121 is a cloud server or is integrated into the same devices as the monitoring device 214 or the controllable valve 222.

In one embodiment, the upper end of the box body 210 has an opening, the colder box 200 comprises a lid matching with the box body 210 and the internal heat insulation space of the lid forming a speed deceleration area. The speed deceleration area is provided below the divider plane, and the divider plane is provided with a plurality of uniformly distributed openings. When the high pressure and low temperature gas enters the speed deceleration area through the air inlet, the air flow is weakened and sinks into the interior of the colder box 200 through the plurality of uniformly distributed openings.

As the liquefied gas from the cryogenic medium container 220 with high pressure (e.g., 2 Mpa) enters into the box body 210 with low pressure (e.g., 0.1 Mpa), bursting of the box body 210 with the gas pressure is possible. For safety reasons, to avoid the box body 210 bursting, in an example of implementation, the box body 210 is equipped with a pressure relief valve. When the pressure inside the box body 210 is greater than the pressure threshold, the pressure relief valve opens, allowing the gas inside the box body 219 to leak in order to reduce the pressure inside the box body 210. In one example, the pressure threshold is 0.2 Mpa by default.

In one example, the pressure relief valve comprises a mechanical pressure relief valve as well as an electronic pressure relief valve. The mechanical pressure relief valve comprises a steel ball. The mechanical pressure relief mechanism utilizes the physical principle that when the pressure on one side is greater than the other, the high pressure side pushes the originally closed steel ball inside the pressure relief valve toward the low pressure side, creating a gap through which the gas naturally exits to achieve relief. The mechanical pressure relief valves do not require electricity and are inexpensive. The electronic pressure relief valve comprises an electronic pressure gauge for detecting the air pressure inside the box body 210 and transmitting data back to the controller 212. When the controller 212 receives a pressure value greater than the pressure threshold, the controller 212 opens the relief valve of the electronic pressure relief valve to allow relief. In one embodiment, to conserve power consumption, the electronic pressure relief valve may be set to detect air pressure only after the controller 212 opens the valve nozzle of the controllable valve 222 and would enter a power saving mode after a period of time.

FIG. 3 illustrates a flow chart of the temperature control method of the cooler box.

The monitoring device 214 periodically performs steps S301 and S302, comprising: measuring a temperature value (Tb) inside the box body 210, and transmitting the measured temperature value (Tb) to the controller 212.

The controller 212 performs step S311 through step S315, specifically comprising the following actions:

The controller 212 receives the measured temperature value (Tb) in step S311 and determines whether the measured temperature value (Tb) is greater than an temperature upper limit value in step S312. When the controller 212 determines that the measured temperature value (Tb) is not greater than the temperature upper limit value, it returns to step S311 and waits to receive a new measured temperature value (Tb). When the controller 212 determines that the measured temperature value (Tb) is greater than the temperature upper limit value, step 313 is performed to calculate the required amount of emission volume (V) of liquid gas based on the difference value (Td) between the measured temperature value (Tb) and a temperature lower limit value and a volume of a cooling space of the box body 210. The controller 212 then converts the required amount of emission volume (V) of the liquid gas to the operating parameters (Vs, Vt) of the controllable valve 222, where Vs is the valve opening state, and Vt is the duration time of maintain Vs. The controller 212 then performs step S314 to transmit the operating parameters (Vs, Vt) to the controllable valve 222 to notify the controllable valve 222 to execute the operating parameters. After transmitting the operating parameters, at step S315, the controller 212 waits for a predetermined cooling time to allow sufficient time for the required decrease of temperature inside the box body 210 and then continues back to the step S311 to process the new measured temperature value received.

The controllable valve 222 performs step S321 and S322, comprising: receiving operating parameters (Vs, Vt) transmitted by the controller 212, controlling the opening state of the valve and a duration of maintaining the opening state to release a desired amount of emission volume (V) of the liquid gas based on the received operating parameters (Vs, Vt), and closing the valve tightly after executing the operating parameters (Vs, Vt).

Taking liquid gas as liquid carbon dioxide, for example, 1.56 grams of liquid carbon dioxide will evaporate into 1 liter of gaseous carbon dioxide, which can absorb heat of 894 joules (J). The formula for heat absorption is H=cmΔT, where c is a specific heat capacity, for example, 1030 for air; m is a mass, for example 1 liter of air=1.3×10⁻³ kg; and ΔT is the temperature difference value. Assuming that the volume of the cooling space of the cooler box 200 is Vb liters, then required amount of emission volume V of the liquid gas for the internal temperature Tb of the cooler box 200 to be decreased to the temperature lower limit value can be calculated as V=f(Vb,Tb,Td)=1030×(Vb×1.3×10⁻³)×(Tb−Td)/894 (Equation 1). The relationship between the liquid gas emission volume V and the operating parameters (Vs, Vt) is: V×1.56=S(Vs)×Vt (Equation 2), where S(Vs) is a function for an opening size of the valve nozzle of the cryogenic medium container 220 corresponding to the emission volume of the liquid gas in grams per second, the function and the pressure value inside the cryogenic medium container 220 has a positive correlation. The function can be established in advance using the cryogenic medium container 220 in a real-world environment.

In Equation 2, a V value may correspond to an infinite number of Vs and Vt values. In one embodiment, the controller 212 determines the valve opening state based on the type of food product insulated within the box body 210. The valve opening state of the controllable valve 222 comprises three values such as closed (Vs=0), half open (Vs=0.5) and fully open (Vs=1.0). Specifically, the controller 212 comprises a human-machine interface that could be used by the user to configure the type of food product to be insulated in the cooler box 200 prior to transport, wherein the cooler box 200 could be preset to insulate a specific food product category, for example, one of fresh food or frozen food. Since the larger the valve opening state, the faster temperature value decreased over a short duration of time, the value of Vs can be configured according to the type of food product being insulated. For example, when the type of the food product to be insulated is frozen food, the temperature needs to be decreased quickly, so the corresponding Vs is 1.0. When the type of the food product to be insulated is fresh food, in order to avoid rapid freezing that may cause cell breakdown or other deterioration, the corresponding Vs is 0.5. In this way, S(Vs) becomes a constant value, and the Vt can be calculated according to the emission volume (V) of the liquid gas and the type of food product (T) to be insulated. For example, when the food product category is frozen food, T is 1 and Vs(T)=1.0; when the food product category is fresh food, T is 2 and Vs(T)=0.5. At this point, Vs=f(T)=Vs(T) , and Vt=f(V, T)=V×1.56/S(Vs(T)) (Equation 3).

FIG. 4 illustrates a block diagram of a cooler box 400 with temperature control. The cooler box 400 comprises a box body 410 and a cryogenic medium container 420. The box body 410 comprises a box 4101 and a top lid 4102 that fits to cover the box 4101.

The box 4101 comprises a first storage area 4103 and a second storage area 4104 for storing different categories of food products. For example, the first storage area 4103 is for storing frozen food products and the second storage area 4104 is for storing fresh food products. The different categories of food products correspond to different storage conditions, and the storage conditions are described in terms of a range of temperature values. The storage conditions for the first storage area 4103 are a first temperature lower limit value extending to a first temperature upper limit value and the storage conditions for the second storage area 4104 are a second temperature lower limit value extending to a second temperature upper limit value.

In one embodiment, the box 4101 is provided with a controller 4105, a first monitoring device 4106 for monitoring the storage conditions of the first storage area 4103, and a second monitoring device 4107 for monitoring the storage conditions of the second storage area 4104. The first monitoring device 4106 is configured to periodically measure the temperature value of the first storage area 4103 and upload it to the controller 4105, and the second monitoring device 4107 is used to periodically measure the temperature value of the second storage area 4104 and upload it to the controller 4105.

In one embodiment, the upper cover 4102 comprises a first speed deceleration area 4108 corresponding to the first storage area 4103 and a second speed deceleration area 4109 corresponding to the second storage area 4104. The top lid 4102 supports a divider plane 4110 on one side of the box 4101. The divider plane 4110 comprises a plurality of openings which correspond to the first speed deceleration area 4108 and the second speed deceleration area 4109 respectively. The top lid 4102 is configured with a controllable valve 421 and a switching device 422, wherein the cryogenic medium container 420, the controllable valve 421 and the switching device 422 are piped to each other, and the switching device 422 is piped to a first air inlet 4111 opened above the first deceleration area 4108 and a second air inlet 4112 opened above the second deceleration area 4109, in a one multiple-input operation. In the embodiment, the switching device 422 is a line switching switch.

In one embodiment, the controller 4105 receives the temperature values uploaded by the first monitoring device 4106 and the second monitoring device 4107. The controller 4105 determines whether the temperature value uploaded by the first monitoring device 4106 is greater than the first temperature upper limit value, and whether the temperature value uploaded by the second monitoring device 4107 is greater than the second temperature upper limit value. When it is determined that the temperature value uploaded by either monitoring device is greater than the corresponding temperature upper limit value, the outlet line of the switching device 422 is controlled to switch to the line corresponding to that monitoring device and the amount of emission volume of the liquid gas is calculated, and the size of emission volume of the liquid gas is converted to a set of operating parameters of the controllable valve 421. The controllable valve 421 is notified to execute the operating the set of operating parameters. The controller 4105, the first monitoring device 4106, the second monitoring device 4107, the controllable valve 421, and the switching device 422 are connected to each other in wireless communication. In other embodiments, the connection between the controller 4105, the first monitoring device 4106, the second monitoring device 4107, the controllable valve 421, and the switching device 422 are wired electrical connections.

In one embodiment, the box 4101 is configured with a first pressure relief valve 4113 and a second pressure relief valve 4114 inside the box 4101 corresponding to the first storage area 4103 and the second storage area 4104 respectively, to ensure that the air pressure in each storage area is not too high.

In other embodiments, the number of storage areas, the space of the speed deceleration area corresponding to the storage area, the aperture of air inlet opening above each speed deceleration area, the number of openings corresponding to each speed deceleration area on the divider plane, the aperture and the distribution method, etc. can be configured differently according to actual needs and are not limited in the present invention.

FIG. 5 illustrates a flow chart of the temperature control method of the cooler box 400.

The first monitoring device 4106 periodically performs step S501 and step S502, comprising: measuring a temperature value (Tb₁) of the first storage area 4103; transmitting a device identifier and the measured temperature value (Tb₁) to the controller 4105.

The second monitoring device 4107 periodically performs step S503 and step S504, comprising: measuring a temperature value (Tb₂) of the second storage area 4104; transmitting a device identifier and the measured temperature value (Tb₂) to the controller 4105.

The controller 4105 performs step S511 trough step S516, specifically comprising the following actions:

The controller 4105 receives the device identifier and the measured temperature value (Tb_(x)); determines a source monitoring device based on the received device identifier, and then determines whether the received measured temperature value (Tb_(x)) is greater than the temperature upper limit value of the storage area corresponding to the source monitoring device. When the controller 4105 determines that the received measured temperature value (Tb_(x)) is not greater than the temperature upper limit value corresponding to the source monitoring device, it returns to step S511 and waits to receive a new measured temperature value (Tb_(x)). When the controller 4105 determines that the received measured temperature value (Tb_(x)) is greater than the temperature upper limit value, step S513 is performed. At step S513, the controller 4105 controls switching of the outlet line of the switching device 422 to the line corresponding to the source monitoring device. Then step S514 is performed, the controller 4105 calculates the required amount of emission volume (V) of the liquid gas based on the difference value (Td) between the received measured temperature value (Tb_(x)), the temperature lower limit value of the storage area corresponding to the source monitoring device and the volume of storage area, and then converts the emission volume of the liquid gas into the operating parameters (Vs, Vt) of the controllable valve 421, where Vs is the valve opening state and Vt is the duration of time to maintain Vs. The controller 4105 then performs step S515 to transmit the operating parameters (Vs, Vt) to the controllable valve 421 to notify the controllable valve 421 to execute the operating parameters; and step S516, the controller 4105, after transmitting the operating parameters to the controllable valve 421, waits for a predetermined cooling time to allow sufficient time for required decrease of temperature inside the storage area corresponding to the source monitoring device before continuing back to step S511.

The controllable valve 421 performs step S521 and S522, comprising: receiving operating parameters (Vs, Vt) transmitted by the controller 4105, controlling the opening state of the valve and a duration of maintaining the opening state to release a desired amount of emission volume (V) of the liquid gas based on the received operating parameters (Vs, Vt), and closing the valve tightly after executing the operating parameters (Vs, Vt).

In summary, the temperature-controlled cooler box and its temperature control method control the liquid gas emission of the cryogenic medium container by controlling the controllable valve to precisely control the temperature change inside the cooler box to ensure that the food product is maintained at the required low temperature environment at all times to ensure food safety.

The embodiments shown and described above are only examples. Many details are often found in the relevant art and many such details are neither shown nor described. Even though numerous characteristics and advantages of the present technology have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the disclosure is illustrative only, and changes may be made in the detail, especially in matters of shape, size, and arrangement of the parts within the principles of the present disclosure, up to and including the full extent established by the broad general meaning of the terms used in the claims. It will therefore be appreciated that the embodiments described above may be modified within the scope of the claims. 

What is claimed is:
 1. A cooler box with a temperature control function, the cooler box comprising: a box body comprising two shells arranged with a space between the two shells, the space being a component installation cavity and an air inlet opening in an inner shell of the two shells; a cryogenic medium container containing liquid gas; a monitoring device installed in the component installation cavity, the monitoring device being adapted to periodically measure an internal temperature inside the box body; a controllable valve installed in the component installation cavity, wherein one end of the controllable valve is connected to the cryogenic medium container through a tube, and another end of the controllable valve is connected to the air inlet through another tube; and a controller installed in the component installation cavity, connected by wireless communication with each of the monitoring device and the controllable valve, wherein the monitoring device is further adapted to periodically upload a measured temperature value to the controller, upon receiving the measured temperature value, the controller performs the following actions: determining whether the measured temperature value is greater than a temperature upper limit value; calculating an emission volume of the liquid gas based on a difference value between the measured temperature value and a temperature lower limit value and a volume of a cooling space of the cooler box when it is determined that the measured temperature value is greater than the temperature upper limit value; converting the emission volume of liquid gas to a set of operating parameters (Vs, Vt) of the controllable valve, where Vs represents a valve opening state and Vt represents a duration time of maintaining Vs; and transmitting the set of operating parameters to the controllable valve to notify the controllable valve to execute the set of operating parameters.
 2. The cooler box of claim 1, wherein the controllable valve closes the valve after executing the set of operating parameters.
 3. The cooler box of claim 1, wherein the controller, after transmitting the set of operating parameters to the controllable valve to notify the controllable valve to execute the set of operating parameters, the controller is further configured to perform: waiting for a predetermined cooling time until a required decrease of temperature inside the box body has reached.
 4. The cooler box of claim 1, wherein the valve opening state comprises closed, half open, and fully open.
 5. The cooler box of claim 1, wherein converting the emission volume of liquid gas to a set of operating parameters (Vs, Vt) of the controllable valve further comprises: determining the valve opening state of the valve according a category of the food product in the cooler box.
 6. A temperature control method for a cooler box, the cooler box comprising: a box body comprising two shells arranged with a space between the two shells, the space being a component installation cavity, and an inner shells of the two shells is configured with an air inlet; a cryogenic medium container containing liquid gas; a monitoring device, a controllable valve and a controller installed in the component installation cavity and connected to each other by wireless communications, the controllable valve is connected to the cryogenic medium container by a tube at one end and to the air inlet by another tube at another end, wherein: the monitoring device is adapted to periodically measure an internal temperature inside the box body and transmit the measured temperature value to the controller; and the controller is adapted to perform the following actions after receiving measured temperature value: determining whether the measured temperature value is greater than a temperature upper limit value; calculating an emission volume of the liquid gas based on a difference value between the measured temperature value and a temperature lower limit value and a volume of a cooling space of the cooler box when it is determined that the measured temperature value is greater than the temperature upper limit value; converting the emission volume of liquid gas to a set of operating parameters (Vs, Vt) of the controllable valve, where Vs represents a valve opening state and Vt represents a duration time of maintaining Vs; and transmitting the set of operating parameters to the controllable valve to notify the controllable valve to execute the set of operating parameters.
 7. The temperature control method of claim 6, wherein the controllable valve closes the valve after executing the set of operating parameters.
 8. The temperature control method of claim 6, wherein the valve opening state comprises closed, half open, and fully open.
 9. The temperature control method of claim 6, wherein the action of converting the emission volume of liquid gas to a set of operating parameters (Vs, Vt) of the controllable valve further comprises: determining the valve opening state of the valve according a category of the food product insulated in the cooler box.
 10. A cooler box with a temperature control function, the cooler box comprising: a box body comprising two shells comprising a component installation cavity between the two shells and an air inlet opening in an inner shell of the two shells; a cryogenic medium container containing liquid gas; and a controllable valve installed in the component installation cavity, one end of the controllable valve is connected to the cryogenic medium container through a tube, and another end of the controllable valve is connected to the air inlet through another tube, the controllable valve is configured with a plurality of sets of operating parameters, each of the plurality of sets of operating parameters comprising a valve opening size and a predetermined duration time of maintaining the valve opening size, the controllable valve, after commencing operation, performing the following action: executing each of the plurality of sets of operating parameters in cycled sequentially until the controllable valve stops operating or a new set of operating parameters is configured. 